Re: AKs - River decision
 

Preflop and flop are good. I'd check/call the turn since the flop was pretty drawless to button's 3-betting range (i.e., he's not raising/capping for a free card ever).

River is a fold, looks like he may have cracked button's top set.

Re: AKs - River decision
 

Easy check/call on the turn and fold on the river, IMO. I'd be very surprised if button didn't have a set and SB didn't have a straight, both which pound your little pair into the ground.